The thickness of the shelf can determine whether or not it can withstand high temperatures without warping. This is usually only an issue if you are working with a large kiln such as a 1227. Since the KM1227-3PK is rated to cone 10 we only recommend 1″ thick half shelves. For kilns designed more for low fire applications it is ok to use a 5/8″ thick shelf which will be lighter.
The quantity you will need will be based on the height of your kiln, the height of the pieces you are putting in your kiln and weather you are using full shelves or half shelves. When you are contemplating how many layers of shelves you want to have on hand, remember, it is always a good idea to have at least 1 element radiating between each layer. If you have a glass kiln with elements radiating down from the lid, you can only fire on one layer because the top shelf will block the radiant heat to the layers below.
Posts are the supports that hold the shelve up. Generally you want to use 3 posts for each shelf you are supporting. Half shelves can share 2 posts on a common layer so you can use 4 posts instead of 6 posts. They come in varying heights from 1″ tall all the way to 12″ tall. The can also be stacked but are more stable when used alone.
You will need to order kiln wash to coat your shelves. Kiln wash is a material that comes in a powdered form that you mix with water to a cream consistency and paint on your shelves.The coating protects the shelves from clay and glaze sticking to them.